A three dimensional—that is solid—object has been built up by depositing a material from an applicator over a flat and horizontal fabrication platform one layer at a time. The platform was below the applicator. Once a layer was deposited and hardened, then another layer was deposited and hardened in contact with the previous layer. Repetition of this process allowed multi-laminate solid objects to be fabricated. This is the basis of techniques such as rapid prototyping.
Material leaks from applicators occur all too frequently. This results in a malformed solid object which may be useless. It may also result in material leaking onto the bearings on which the platform moves, thereby interfering with the operation of the system. Prior art apparatus have tried to solve this problem by active pressure control of the liquid material and storing of the material a distance from the deposition device. This approach is, however, typically not very effective and makes the apparatus overly complex.